I grabbed the same iso's you've mentioned with the same timestamp. (5/01)official as well as daily,and also wrote to USB, but i used "dd" instead and they booted flawless...There could be something wrong with unetbootin (wouldn't be the first time),but the iso's i downloaded are ok.

downloaded, and put on a stick using "dd"Nothing wrong.It just booted., so something must go very wrong on your side.What hardware specs do you have?I saw that /dev/sda3 which is unreadable.Seems you have problems on accessing disks, too.